This invention relates to devices for providing access to a bodily cavity through the skin. Heretofore the art has generally utilized percutaneous devices for access. Percutaneous access devices are useful when frequent or long-term access to the body is required, as in kidney dialysis, drug delivery, intravenous feeding, ostomies, and transmission of energy to intra-corporeal blood pumps. Practical devices for long-term skin penetration in humans, however, have not been generally successful because skin adjacent to the implanted devices will not heal to form a tight barrier to infection. Instead, when a foreign device is implanted for percutaneous access, epidermal cells begin to migrate, each seeking to surround itself completely with other similar cells. The epidermal cells thus grow down the sides of the device in an attempt to expel it. Deep sinus tracts form and body fluids are exuded at the interface between the device and adjacent tissue, forming a bed for infection. The percutaneous device, if not expelled spontaneously, must be removed to allow the infection to be cured.
Another drawback of presently available skin penetration devices relates to the difficulty of correcting problems with tubes mounted to, and extending through, such devices. Catheter tubes which are used, for example, in continuous ambulatory peritoneal dialysis or continuous infusion of drugs may become misaligned, kinked, blocked or coated with fibrin. With existing technology such catheters cannot readily be removed without disturbing the percutaneous access device, and thus they must be surgically removed and replaced with another access device at a different site. Current technology does not, therefore, readily permit multiple use of an implanted percutaneous access device wherein one catheter may be substituted for another, nor does it allow catheter removal followed by plugging of the device for use at a later time.
Furthermore, advances in surgical techniques coupled with increased emphasis on outpatient surgery have fueled the need for safe, reliable, non-traumatic access for non-invasive intra-body diagnostic and therapeutic follow-up procedures in ambulatory patients.
One such advance is the new surgical technique known as video-laparoscopy. A tubular instrument of small diameter, having a video lens and sampling, biopsy and dissecting instruments, as well as laser output at its tip, is inserted through a small opening through the skin and muscle tissue of a patient. A skilled surgeon directs the tip of instrument to the site of problematic tissue. The laser output is then employed to cut through or destroy problematic tissue.
While this technique represents a major advance over traditional surgical procedures for treatment of a variety of intraabdominal diseases, including cancer, repeated invasive access under general anesthesia is required in many of these instances.